Crank-wheel shield for mowing machines



Sept. 3, 1929. A. lARADlsE CRANK WHEEL SHIEIJD FOR MOWING MACHINES Filed 001', 2, 1926 Patented Sept. 3, 1929.

UNITED STATES PATENT OFFICE.

LOUIS A. PARADISE, OF MOLINE, ILLINOIS, ASSIGNOR TO DEERE & COMPANY, OF

MOLINE, ILLINOIS, A CORPORATION OF ILLINOIS. Y

CRANK-WHEEL SHIELD FOR MOWING MACHINES.

Application filed October 2, 1926. Serial No. 139,044.

The resent invention relates to a crank wheel s ield for mowing machines.

In the conventional type of mower the reciprocation of the sickle or cutter blade, which does the mowing, is generally effected through a crank wheel and pitman disposed at the front of the mower, the pitman being connected at one end to the crank wheel and at the other end to the sickle and extending transversely of the machine. The crank wheel is mounted on the forward end of a drive shaft extending back to suitable gearing I connecting to one of the mower wheels, from which the power necessary to reciprocate the sickle is derived.

In this conventional mower design the crank wheel is generally situated, at a relatively low point in the front of the machine, and it is customary to protect the same against strikinghummocks orbecoming fouled with grass etc. by partially enclosing the same with a bowl shaped member generally cast integral with the frame. The front of this protecting bowl is usually closed by a guard or shield which, desirably, is removable so that the crank wheel and its drive shaft can be removed from the machine by withdrawing the same'lengthwise through the open front of the bowl.

My invention pertains toimprovements in the particular construction ofsuch guard or shield. I-Ieretofore, this unit has been constructed as a single casting which, because of the considerable size of shield necessary to cover the front end of the aforesaid bowl, has involved considerable weight and cost of metal in the casting. The object of the present invention is to produce a lighter, less expensive and more durable form of shield by providing one whereinthe upper part of the unit is a casting and the lower part is a sheet metal plate. The upper part is preferably a casting in order that it may be threaded for receiving the end of the drag link which serves adjustably to predetermine the registry between the ledger plate and the knives of the cutter blade, as will hereinafter appear. The lower portion functions primarily to prevent hummocks, grass etc. from interfering with the crank wheel and pitman, and this lower portion can advantageously consist of a sheet metal plate.

A further feature of my invention resides in the manner of joining the sheet metal plate to the casting constituting the upper portion of the shield, such being accomplished by embedding the plate in the casting in the molding of the latter. This casting, by extending across the upper horizontal portion of the shield, serves to stiflt'e the sheet metal plate.

Referring to the accompanying drawings illustrating a preferred embodiment invention:

Figure 1 is a fragmentary plan view of a mower of conventional design, illustrating my improved shield on the front of the bowl which protects the crank wheel and pitman connection.v

Fig. 2 is a front view of the crank wheel, proltecting bowl and front shield, on a larger sca e.

Fig. 3 is a transverse sectional view through the shield, taken on the plane of the line 3-3 of Fig. 2, and

Fig. 4 is a front elevational view of the sheet metal plate before the same has been embedded in the upper cast portion of the shield.

In the conventional type of mower chosen for illustration in Figure 1, the main frame 5 is supported on two laterally separated wheels 6+6. The cutter bar, fragmentarily illustrated at 8, extends laterally from the main frame 5, at a point infront of one of the wheels 6. The sickle of this cutter bar is reciprocated through a pitman 9 which extends across the front of the machine and connects to a crank pin 10 projecting from the front face of the crank wheel 11. Such crank wheel is mounted on a shaft 12 which extends of my backwardly through a journal portion 13 of v The crank wheel 11 and pitman 9 are situated relatively close to the ground so that the pitman will have a substantially straight line reciprocation with the sickle, and because of this disposal, it is customary to protect the crank wheel and pitman against striking hummocks, or having grass, stubble etc. be come entangled therein, by extending a bowl shaped protecting portion 14 forwardly and below the crank wheel. This bowl shaped portion is usually cast integral with the journal portion 13 of the main frame, and is preferably arcuate in form, as viewed from the end thereof, (Fig. 2) so as to embrace the outer side and part of the underside of the crank wheel. To the end of permitting ready removal of the crank wheel 11 and its shaft 12, by pulling from the front end of the journal portion 13, it is customary to form the bowl portion 14 with an open front end, and to close this end by a removable shield.

Heretofore, this removable shield has been constructed as a unitary casting, generally of semi-circular form to coincide substantially with the curved contour of the bowl. As previously stated, such prior practice of constructing the shield as a unitary casting has involved an objectionable weight and cost of metal, which it is the object of the present invention to avoid.

According to my invention, I construct the shield with an upper cast portion 16 and a lower sheet metal portion 17, The upper cast portion reinforces and lends a desired rigidity to the shield, and the lower sheet metal portion serves as an adequate closure or barrier against the entrance of dirt, grass etc. around the crank wheel and pitman. By constructing the upper portion as acasting, the formation of certain attaching port-ions is also facilitated. Forexample, the shield desirably carries a threaded socket 18 for receiving the threaded end of a drag link or brace bar 19 extending transversely of the machine in front of the pitman 9. This drag link functions as a bracing support for the cutter bar 8 and also serves as an adjustable spacing member for adjusting the registry between the ledger plate and cutter knives of the cutter bar 8. Such adjustment is obtained by threading the drag link and shield back or forth relatively to each other. The upper cast portion is also formed with an apertured lug 21 adapted toreceive a cap screw or bolt 22 by which the shield and drag link are connected to the bowl portion 14.

Formed as an integral part of the cast portion 16 is a depending flange 23, preferably extending across the width of the shield and directly below the tubular socket portion 18. The sheet metal portion 17 preferably consists of a sheet steel plate of arcuate form having its flat upper edge anchored in the flange 23. This attachment is effected by embeddlng the flat upper edge of the plate in the flange 23 during the molding of the cast portion 16. As shown in Fig. 4, the sheet metal plate has a plurality of elongated openings 24 which are punched therein in the operation of stamping out the plate, and when the metal is flowed into the mold in the formation of the cast portion 16 it will fill these openings and thereby rigidly unite the two shield portions 16 and 17. I have found such method of joining these two portions to be preferable to bolted or riveted attachments, as the latter are susceptible to loosening with consequent rattling, owing to the high speed vibration generally existing at the crank wheel 11.

The result is a shield which is much lighter than the former cast metal shield and which is less expensive. Moreover, the present shield is more durable than the former shield in that the sheet metal part 17 will yield when striking a rock or other unyielding projection, where the former cast metal shield would be susceptible to cracking.

What I claim as my invention and desire to secure by Letters Patent, is

1. A shield for mounting over the front end of the crank wheel protecting bowl of a mower, comprising an upper cast portion extending substantially horizontally and having a threaded socket for receiving the end of a drag link and having an apertured ear for bolting to the protecting bowl, and a sheet metal plate embedded in said casting.

2. A shield for mounting over the front end of the crank wheel protecting bowl of a mower, comprisin a threaded tubular socket portion having a olting lug at one end and a flange depending from said socket portion, and a sheet steel plate embedded in said flange in the casting of the latter, said plate having openings therein which are filled by the flange metal in the molding of the latter.

8. A crank wheel shield for mowers and the like comprising an independently formed sheet metal member defining a lower yield able portion of the shield, and an upper member defining the upper transverse edge of the shield of cast metal cast fast to said sheet met a1 member.

4. A crank wheel shield for mowers and the like comprising an independently formed lower sheet metal member, and an upper member made fast to said lower member in the casting operation, said upper member having a threaded socket therein. 7

5. A shield for mounting over the front end of the crank wheel protecting bowl of a mower, comprising a'independently formed sheet metal member defining the lower curved edge of the shield, and an upper member defining the upper transverse edge of the shield cast fast to said sheet metal member, said upper member being provided with means for attaching to a connecting member extending transversely of the mower.

6. A shield for mounting over the front the upper transverse edge of the shield cast end of the crank Wheel protecting boWl of a fast to said sheet metal member, the metal mower, comprising an independently formed of the upper member filling the openings in 1 sheet metal member defining the lower curved the sheet metal member in the casting opera- 5 edge of the shield, said sheet metal member tion.

being provided with openings therein near its upper edge, and an upper member defining LOUIS A. PARADISE. 

